Fuel-consumption indicator



F. W. DAVIS FUEL CONSUMPTION INDICATOR Filed Jan 1922 Sept 1, 1925.

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Patented Sept. 1, 1925; I

UNITED STATES PATENT OFFICE.

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Application filed January 28, 1922. Serial No. 581,021.

To all whom it may concern:

Be it known that I, FRANCIS W. Dnvrs, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented a new and useful Improvement in Fuel-Consumption Indicators, of which the following is a specification.

My invention relates to improvements in liquid fuel consum tion indicatorsfor 'vehicles operated by internal combustion engines.

One of the objects of m invention is to provide an extremely simp e indicator referably arran ed so as to be readily visible from the drivers seat for showin at all times while the vehicle is runnln the amount of gasoline or other liquid fue consumed by t e engine. More specifically my invention is designed for directly indicating the number of miles per gallon .of fuel obtained b a vehicle engine at different speeds of travail 1 For the pur ose of disclosin my invention I have il ustrated one em odiment in the accompanying drawings, which:

- Fig. 1 is a fra entary side elevation of a vehicle operate by an internal combustion engine and which is provided with a fuel consumption indicator embodying the invention,

Fig. 2 is a face view of a speedometer with which the fuel consumption indicator is associated,

Fig. 3.is a fragmentar sectional plan of a portion of the rate 0 flow indicator,

Fig. 4 is a fragmentary-perspective view of another portion thereof, and

Fig. 5 is a development 19. out of the cahbrations on the rotatable rum of the indicator.

In the embodiment of the invention illustrated a Venturi tube 1 is provided in the fuel supply or feed pipe 2 leading to the -carburetor 3 of an internal combustion engine 4 of the vehicle 5. This Venturi tube may take the form of a separate tube 1nserted in the feed line or, if desired, may be formed inte rally with the feed pipe. As usual, this tu e has a restricted waist 6 which tapers from the full diameter of the pipe in both directions. Suitable openings or ports 7 are provided in the intake end of this tube, which ports communicate with a conduit or pipe 8. This conduit preferably has a portion 9 surrounding the tube and ports, forming an annular channel around that portion of the feed tube having the ports 7, which 1preferably take the form of a series of sma openings in the wall of the tube. A similar conduit 10 is connected with the restricted waist of the Venturi tube which likewise is provided with ports or openings 11 and these two conduits are connected to the resppctive legs 12 and 13 of a U shaped glass tu e 14. The U-tube contains anindicating liquid which is preferabl colored so as to b readily observed an is of greater specific gravity than gasoline and of such a composition that it will not dissolve in or mix with the gasoline or liquid'fuel for the engine.

The structure thus above described provides a means for determining the quantity of fuel passing through the feed pipe of the engine in a given period of time. The 'dif-' ference in pressure between the liquid fuel in the enlarged portion of the Venturi tube and that in the restricted waist of the Venturi tube, which difl'erence will vary with the rate at which the fuel passes throu h the feed pipe 2, will be indicated b t e height of the liquid in the legs of t e U- tube, thereby indicating the rate of flow of the fuel through the fuel feed pipeof the en ine, when read in connection with a suitab A calibrated scale 15. This scale isprefera ly calibrated to indicate gallons per hour passing through the feed pipe and may be marked on that leg of the U-tube connected with the restricted waist of the Venturi tube or on a face plate with which the tube is arranged to be associated and opposite the movable member adapted to move to different positions in accordance with the speed at which the vehicle is traveling. The rotatable cup or head 16 of a speedometer 17 is preferably utilized for this purpose. The

speedometer, which may be of known or any suitable type, is, as usual, driven from some appropriate moving part of the vehicle and has the usual 'call'brated scale 18 preferably at the top edge of the cup which indicates the miles per hour at which the vehicle is moving. The cup is made longer than is usual in the ordinary speedometer or'is provided with a skirt or extension on these fuel hour.

which is providedgraduated scales 19 adapted to cooperate with the scale 15 of the U-tube in such a way as to indicate the distance in miles traveled by the vehicle per gallon of fuel consumed by the engine at the different speeds of the vehicle. These scales, as shown, are arranged in vertical columns on the cup and are calibrated to indicate the number of miles per gallon of fuel consumed by the engine. To'this end the vertical scales 19 have a definite relation to the speed scale 18 which is arranged horizontally around the cup to indicate the miles per hour at which the vehicle is traveling. I have illustrated only a few of consumption scales 19. Those illustrated show'the number of gallons of. fuel per mile consumed by the engine when the vehicle is running at ten, thirty, sixty, sixty-five and seventy miles respectively per Each of the scales 19 is arranged vertically in line with its related speed indication on the scale 18 so as to show the miles per gallon consumption of fuel when the vehicle is traveling at the speed indicated by the number on the scale 18 in alinement with said vertical scale 19. These scales 19, however, are merely illustrative and a greater number of scales can be used if desired. The cup of the speedometer 1s -arranged adjacent to that leg 13 of the U-shaped tube connected with the restricted waist of the Venturi tube in such a manner that the vertical scales on the speedometer cup can be readily read in cooperation with the level of the liquid in the leg 13 of the U-shaped tube. To this end the U-shaped tube, as well as the speedometer cup is mounted behind the face plate 21 of the speedometer, which face plate is provided with a vertical slot 22 therein through which the tube 13 and one of the scales 19 on the speedometer cup can be observed. If desired, the scale 15, instead of being placed directly upon the tube, may be placed on one vertical edge of the slot or, as shown in the drawings, a scale 23 indicating the gallons per hour of fuel consumed by the engine is marked on the face plate at the edge of the slot 22 which coincides with the graduations 15 on the glass tube itself. The height of the column of liquid in the leg 13 of the U-tube varies with changes in the feed of the fuel to the engine, and the number on the scale 23 opposite the top of the liquid column at any time will show the amount of fuel per hour being consumed, while the 1 number on the exposed scale 19 opposite the At one side of the slot are the usual openings 25 in the face of the speedometer through Which the figures of an odometer, mounted in the speedometer casing, maybe read. The structure thus provided is'preferably mounted on the instrument board of the vehicle and the driver may thus readily observe his total mileage, his trip mileage and at any time the speed at which he is travelling and the miles per gallon of fuel consumed when travellingat said speed. In addition he may readily observe the allons of fuel consumed per hour either while the vehicle is running or when the engine is running idle.

I claim as my invention:

1. In a fuel consumption indicator for an explosive engine having a Venturi meter through which the liquid fuel flows to the engine, movable means actuated by the liquid'in the vertical pipes of said Venturi meter and responsive to variations in the hei ht of the liquid in said vertical pipes, an a scale cooperating with said movable means and calibrated to indicate the rate' of consumption of fuel by the engine. 2. In a fuel consumption indicator for explosive engines of vehicles, having a Venturi tube arranged in the fuel feedpipe of said engine, a U-shaped transparent tube containing an indicating liquid, the legs of said U-tube ccmmunicating respectively with the enlarged and restricted portions of said Venturi tube whereby variations in the flow of fuel in said Venturi tube will cause moveplosive engines of vehicles, having a Venturi tube arranged in the fuel feed ipe of the engine, a-U-shaped transparent tu e containing an indicating liquid and having the vertical legs thereof communicating respectively with the enlarged portion of the Venturi tube on the intake end thereof and with the restricted portion of the tube whereby variations in the flow of fuel in said Venturi tube will cause movement of said indicating liquid to different levels in said U- tube, a speedometer cup movable to different positions in accordance with different speeds of the vehicle and having indicia thereon calibrated to cooperate with the different levels of said indicatin liquid to indicate the rate of consumption 0 fuel by the engine at different speeds of the vehicle.

4. In a fuel consumption indicator for ex; plosive engines, having a fuel feed pipe with a Venturi tube in said feed pipe, a U-shaped transparent tube containing an indicating liqui the legs of said U-tube communicating respectively with the enlarged and restricted portions of said Venturi tube whereby variations in the flow of fuel in said Venturi tube will cause movement of said indicating liquid in said U-tube, and a scale cooperating with said indicating liquid and calibrated to indicate the rateof consumption of fuel by the engine.

-5. In a fuel consumption indicator for explosive engines, having a Venturi tube through which the liquid fuel-flows to the engine, ali uid column operatively connected with said Venturi tube so that the position of the column changes with variations in the flow-of fuel through the Venturi tube, and a scale cooperating with said liquid coltube through which the liquid fuel flows t0 the engine, a liquid column operativel connected with said Venturi tube so that t e'position of the column changes with variations in the flow of fuel through the Venturi tube,

and a vehicle speed indicator having a mem-- her which changes position with variations in the speed of the vehicle and is provided with a scale which-cooperates with said liquid column to indicate the rate of consum tion of fuel by'the engine at diiferentspee of the vehicle. 7

FRANCIS WJDAVIS. 

